Abstract: The novel compound N-[(3-aminoproypl)aminobutyl]-Z-(F-guandino-3-hydroxyheptanamido)-2-methox yethanamide or a pharmaceutically acceptable salt thereof which has antitumor activity in experimental animals.

Abstract: N-[4-[(3-aminopropyl)amino]butyl]-2,2-dihydroxyethanamide is an immunostimulant in animals and an intermediate for synthesis of the antibiotic BMG162-aF2.

Abstract: N-[4-(3-Aminopropyl)aminobutyl]-2-(.omega.-guanidino-fatty acid-amido)-2-substituted-ethanamides represented by the general formula ##STR1## wherein Y represents --(CH.sub.2 --CH.sub.2 --, --CH.dbd.CH or ##STR2## R represents a hydrogen atom, an alkyl group of 1 to 4 carbon atoms which may have a hydroxyl group as substituent, or a benzyl group, and n is an integer of from 1 to 8, provided that when Y is ##STR3## and n is 4, R represents the groups other than the hydrogen atom; a salt thereof having antitumor activity in experimental animal tumors and a process for the preparation thereof is provided.

Abstract: As new compounds are provided 3-demethoxyistamycin B and 3-demethoxy-2"-N-formimidoylistamycin B which each is useful as antibacterial agent because of its high antibacterial activity against a wide variety of gram-positive and gram-negative bacteria including mycobacteria. These new compounds may be produced by removal of the 3-hydroxyl group of an N,O-protected 3-O-demethylistamycin B.sub.o, followed by glycylation of the liberated 4-methylamino group and, further, if necessary, followed by formimidoylation of the 2"-amino group of an intermediate N-protected 3-demethoxyistamycin B derivative.

Abstract: A new istamycin A derivative called di-N.sup.6', O.sup.3 -demethylistamycin A exhibits a high antibacterial activity against various bacteria, particularly Pseudomonas aeruginosa. This compound can be prepared by selective acylation of the methylamino group at the 4-position of 1,2',6'-tri-N-protected N.sup.4 -deglycyl-di-N.sup.6', O.sup.3 -demethylistamycin A with glycine or an N-protected derivative thereof, followed by N-deprotection.

Abstract: The novel compound represented by the general formula (I) ##STR1## (wherein R represents a hydrogen atom, an alkanoyl group of 1 to 14 carbon atoms, or an arylcarbonyl group), and an acid addition salt thereof [on condition that when R is a hydrogen atom, the hydrochloride exhibits an optical rotation of [.alpha.].sub.D.sup.22 -1.degree. .+-.2.degree. (c, 2 water)] has antitumor activity in experimental animals.